Ro lung-mill for making seamless tubes



(No Model.) I 4Sheets-Sheet 1. I

W. HEGKERT. ROLLING MILL FOR MAKING SEAMLESS TUBES.

No. 429,623. Patented June 10, 1890.

(No Model.) w 4 SHeetS- -Sheet 2.

W. HEOKERT. ROLLI'NG MILL FOR MAKING SEAMLESS TUBES.

No. 429,623. Patented June 10,1890.

W1] WESSES (No Model.) 4 Sheets-Sheet s. y

W. HEGKERT.

I ROLLING MILL FOR MAKING SEAMLESS TUBES. No. 429,623.

Patented June 10 1890.

WZIWESSZ'S v 1130mm (No Model.) 4 Sheets-Sheet 4.

W. HEGKERT.

ROLLING MILL FOR MAKING SEAMLESS TUBES.

No. 429,623., Patented June 10, 1890.

WJIWESSES man I072 NiTED STATES PATENT OFFICE.

VILLIAM HEOKERT, OF-FINDLAY, OHIO.

ROLLING-MILL FOR MAKING SEAMLESS TUBES.

SPECIFICATION forming part of Letters Patent No. 429,623, dated June 10, 1890.

Application filed March 1, 1890. Serial No. 342,216. (No model.)

To all whom, it may concern.-

Be it known that I, WILLIAM HECKERT, a

citizen of the United States, residing at Find lay, in the county of Hancock and State of Ohio, have invented certain new and useful Improvements in Rolling Mills; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to Which it appertains to make and use the same.

My invention consists of certain improve-' ments in rolling-mills for rolling seamless hollow tubes,hereinafter to be more particularly described and claimed.

In the drawings, Figurel representsa side view of the bed plate or frame and housings on the same. Fig. 2 is a plan view of a portion of the frame with the housings thereon and the gearing for the rolls. Fig. 3 is an end view of the same. Fig. 4 is a top, and Fig. 5 a side, view of the roll-housings. Fig. 6 is an end view of the bed-plate, showing the feed-gear. Fig. 7 is a perspective view of the mandrel. Figs. 8, 9, 10, 11, and 12 are detail cross-sections of different sections of the mandrel and the ingot being rolled thereon; and Fig. 13 is an end view of the mandrel.

Efforts have frequently been made to roll seamless hollow tubing from a continuous hollow ingot by means of a mandrel passed through said ingot and successive pairs of Vertical and horizontal grooved rolls. Among the disadvantages and difficulties incurred in the usual form of rolling-mill designed for this purpose have been the great Weight and cumbersomeness of the gearing, the roll-housings, and various parts of the main frame or bed-plate, which have been difficult to handle singly, and from the nature of their arrangement frequently required the removal of a great many parts in order to get at that member of the combination which needed repair or adjustment; and also the difficulty of properly centering the mandrel Within the hollow ingot and pipe when it is being rolled and of bringing the reducing action of the rolls upon the bottom rather than upon the sides of the grooves therein. In the use of the tapering mandrel, which has been generally employed in machines of this kind, it has occurred that the pipe emerging from one set of rolls passed on to a second set, in which it was to be still further reduced upon a portion of the mandrel of less diameter than the internal diameter of the tube itself. As a result the first reducing action of this second set of rolls would f requenily crush inthe pipe at one side and force the mandrel to the other side, whereupon, the metal closing around it,

an imperfect pipe is formed, one side being much thicker than the other, the internal and external circumferences being eccentric instead of concentric one with another. To obviate these difficulties above set out, and others not specifically enumerated, I have designed the improved rolling-mill illustrated,

in which A represents the main frame or bed-plate, upon which the feed apparatus E and the rollhousings B B B" 13', &c., are mounted. These roll-housings receive the several sets of rolls R R, and are so arranged, as best shown in Figs. 2 and 3, that each set of rolls is inclined at an angle of aboutforty-five degrees to the horizontal plane; but the consecutive sets of rolls are at about right angles one to another. The rolls R R are mounted in suitable bearings of the usual form placed in said housings, and the adjustment of said rolls is brought about by the use of the screws F, mounted in'caps G upon the housings according to the usual construction. The caps G are held to the housings bybolts g g, and by forming one end of the cap 7' G, as shown in the dotted-line figure, Fig. 4:, the caps can be swung to one side and the rolls removed without necessitating the removal of the caps. The housings have suitable feet J J, &c., by which they are bolted to the bed-plate or frame A.

The motive power is transmitted to each set of rolls through the main shaft WV. (Shown in Fig. 2.) Upon this shaft WV are mounted one or more bevel-wheels V V'.,which gear with corresponding bevel-wheels Z Z 5 upon the shafts S S, which are mounted in suitable bearings upon the bed-plate, and are parallel to the length of said bed-plate. At proper points on these shafts S S are mounted bevel-wheels z a, which gear with corre- IOO sponding bevel-wheels z 2, connected with the various sets of rolls, thereby giving a rotary movement thereto. These bevel-wheels may of course be cast solid and keyed upon the shafts, or they may preferably be made in two parts and fastened together by suitable bolts and lugs in the well-known way. \Vith this latterarrangement, upon the breakage of any gear-wheel by reason of too great a strain brought thereon, the fragments of the gear-wheel may be removed and a new one put in its place without disturbing other portions of the rolling-mill and causing but a slight delay.

The apparatus for handling and feeding the ingot to the rolls consists of the bracket 0, in which the ingot I maybe dropped from an overhead traveling crane, and which is vertically adjustable by means of the slots 0 and bolts 0' therein. The mandrel M is mounted 011 and practically a continuation of the piston-rod H, connected with the piston operating in the com pressed-air or water cylinder E. The piston and mandrel are supported on the sliding cross-head N, and the motion of the piston is controlled by compressed air, steam, or water, admitted alternately at either end of the cylinder E by means of the valves in the valve-chests e e, which said valves are connected by the valve-rod E',which is oscillated by means of the lever P. The lever P is pivoted to the frame in any suitable way, as at p, and terminates in a handle 1). It may be locked in any position by means of the pin a being dropped into suitable holes in the quadrant U.

The perforated pipe X is supplied with water through the pipe in from any suitable source, which is controlled by the valve XV, opened by the lever \V coming in contact with the cross-head N at the end of its backward stroke, thereby sprinkling the mandrel M and cooling the same.

On the forward motion of the mandrel into the ingot I the spring closes the valve WV and the flow of water so discharged isshut off. The water after cooling the mandrel, as above described, drops into a drip-pan X.

The mandrel M is composed of a series of sections m m m, &c., which are each oval in shape and are so placed that the major axis of each section is just equal in length of the minor axis of the preceding section and is parallel thereto, the difference between the major axis and the minor axis of any one section gradually diminishing until the mandrel terminates with its last and smallest section a true circle. In other words, the ellipses of the successive sections diminish in eccentricity until the limiting condition (the circle) is reached, it being understood that a circle may be spoken of as an ellipse whose eccentricity is zero. This mandrel of course may be made of one piece; but the preferable construction is to form it of a stem T, upon which the sections on m m, 850., are slid and held in position by suitable headless set-screws K. The nut Q, on the end of the mandrel also serves to hold all the sections in place upon the stem.

The method of operation of my invention is the following: The heated ingot I being placed on the bracket 0, the leverP is given a move ment sufficient to open the valve into the valvechest e and the inflowing air or steam forces the piston-rod H and mandrel M forward, so that the mandrel passes into the ingot and into the passes of the rolls. \Vhen the first section in hasenteredthe ingot, the internal diameter of said ingot being a little greater than the longer diameter or axis of the said first section m,it picks it up and forces it into the first pass of the rolls R R, the mandrel stopping at this point and remaining at rest during the process of rolling which follows. The rolls pull the ingot through them onto the second section m of the mandrel, thereby reducing it from the form shown at O in dotted lines, Fig. 8, to that shown in full lines 0 in the same figure. From this set of rolls the pipe is forced onto the next section, (m of the mandrel,) coming onto it in the shape 0, as shown in dotted lines in Fig. 5). These rolls crush and reduce the pipe down to the shape 0, as shown in full lines in Fig.9. In the same manner the reduction on the remaining sections of the mandrel and within the remaining sets of rolls goes through the shapes 0 0 to the finished shape O, as shown in Figs. 10, 11, and 19. The final section of the mandrel is a true circle, as is also the pass in the last set of rolls, and the product of the rolling-millis a seamless tube of perfect circular cross-section and equal thickness of walls throughout. lyreversing the lever P the steam or air enters the other end of the cylinder E and withdraws the mandrel M. At the last portion of the travel of the cross'head N the lever W is struck, which opens the valve XV and permits water to enter through the pipe to and fill the perforated pipe X, from which it drops upon the mandrel, cooling the same. Then another ingot has been placed in the bracket 0 and the mandrel is given its forward motion, the spiral spring S operates the lever \V to close the valve lVand the flow of water is shut off.

The advantages of this improved rollingmill are evident in its simplicity and lightness, combined with strength. It is evident that with a break down at any point, produced by any cause, the part damaged can be readily replaced without disturbing other parts of the rolling-mill. It is also evident that as the pipe passes off one section of the mandrel onto the next, coming onto it in the shape shown in any one of the dotted-line figures, Figs. 8 to 12, it is positively held and centered by the mandrel-section by virtue of the fact that the major axis of the elliptical pass of the rolls at this point is equal to the minor axis of the ellipse to which the outer surface of the pipe has been formed by the preceding set of rolls, while the inner surface of the pipe is shaped to an ellipse whose minor axis is just equal to the major axis of the said mandrel-section. Moreover, in view of the ICC IIO

fact that the main reduction of the pipe by the rolls is always in the direction of the major axis :r of the ellipse formed by the pipes cross-section, and that said major axis is always at right angles to the axis of the rolls which is parallel to the minor axis y y, (reference being made to the dotted section 0, Fig. 8,) the said reduction is nearly all done by the bottom portion of the groove in each roll, and little or no pressure is brought upon the sides of the grooves, so that there is no tendency to clog the rolls or tear the stock by virtue of the different rates of speed at which the bottom of the groove and the sides of the same are traveling, on account of their being nearer to or farther from the center of the revolving roll. Again, whenever the action of any set of rolls has worn down the end of.

the mandrel-section, which terminates in the bight of said rolls, by the action of the pipe which is drawn down over the end of each section to the lesser diameter of the next section,

- the sections of the mandrel can be removed,

put in a lathe, and have a portion of their ends turned down to the shape of the next section and the entire mandrel moved forward on its stem. These operations may be repeated until the mandrel is entirely worn out and new sections then put on.

It will be noticed. that throughout the operation the major axis of the tube is presented to the minor axis of the mandrel-section, leaving a crescent-shaped opening between the two, the action of the successive sets of rolls closing the tube to the form of the mandrelsections with little or no friction and wear on the same.

While Ihave described the passes of the rolls and the sections of the mandrel hereto; fore in general terms asbeing reduced copies one of the other, and while such an arrangement would work,producing a finished pipe of the same thickness of wall as the original ingot, but of much less diameter, in the preferred form of my invention the passes of the rolls and the sections of mandrel corresponding thereto are arranged as shown in the drawings, Figs. 8 to 12, in which the ellipse of the mandrel-section is of less eccentricity, more nearly approaching the circle than the ellipse of the corresponding roll-pass. This being the case, the wall of the pipe which corresponds to the side of the ellipse is rolled thinner than that at the end, and as said side portion of each ellipse becomes the end portion of the succeeding ellipse, it is evident that the thickness of wall of the pipe, as well as its diameter, would be rapidly and evenly reduced, so that the finished pipe can be of any thickness less than the thickness of the original ingot. At the same time the essential point of my invention is not lost sight of, to wit: that the dimension of each pass of the roll which is parallel to the axis of that set of rolls shall be just equal to and not less than the dimension of the preceding pass of the rolls which is at right angles to the axes of said preceding set of rolls, so that there need be no work done by the sides of the grooves of the rolls, but all such reducing work is brought upon the bottom of the grooves. IL- is also evident that while the arrangement or alternating ellipses specially described herein is the best arrangement of roll -passes and mandrel sections for the rapid and even reduction of the ingot, yet such reduction might be brought about by alternating sections of different shapes and irregular form or of alternating elliptical and circular shapes, so long as the diiferences in the pass of each roll and the cross-section of the mandrel above referred to are preserved, or so long as the arrangement of succeeding parallel dimensions by which all work is taken from the sides of the roll-grooves is preserved.

Having therefore described my invention, what I claim as new, and desire to protect by Letters Patent, is

1. The combination of two or more sets of grooved rolls arranged about at right angles one to another, the passes of said rolls being of an elliptical form, the major axis of each ellipse being parallel to the axis of the rolls of that set, and the minor axis of each pass being exactly equal. in length to the major axis of the ellipse of the succeeding pass, together with a mandrel composed of sections equal in length to the distance between the center of one set of rolls and the center of the next, the cross-section of each of said sections of mandrel being an ellipse whose major and minor axes are parallel to the major and minor axes, respectively, of the ellipse of the corresponding roll-pass, the cross-section of the mandrel being an ellipse of less eccentricity than the ellipse of the roll-pass, substantially as described.

2. The combination of two or more sets of grooved rolls arranged about at right angles one to another, the passes of said rolls being of varying shapes, but so arranged that the least dimension of each pass is at right angles to the axes of that set of rolls and exactly equal to the parallel dimension of the pass of the succeeding set of rolls, said latter dimension being parallel to the axes of said succeeding set of rolls, substantially as described.

3. A mandrel consisting of a series of sections of varying shapes so arranged that theleast diameter of any one section is exactly equal to the greatest diameter of the succeeding section and parallel thereto, substantially as described.

4. The combination of two or more sets of grooved rolls arranged about at right angles one to another, the passes of said rolls being of varying shapes, butso arranged that the less dimension of each pass is at right angles to the axes of that set of rolls and exactly equal to the parallel dimension of the pass of the succeeding set of rolls, together with a mandrel consisting of a series of sections ITO of varying shapes approximately correspondin g to the shape of the corresponding passes of the rolls, and arranged so that the least diameter of any one mandrel-section is exactly equal to the greatest diameter of the succeeding section and parallel thereto, substantially as described.

5. The combination of two or more sets of grooved rolls arranged about at right angles one to another, the passes of said rolls being of elliptical form, the major axis of each ellipse being parallel to the axis of the rolls of that set, and the minor axis of each pass being exactly equal in length to the major axis of the ellipse of the succeeding pass, substantially as described.

6. The combination of two or more sets of grooved rolls arranged about at right angles one to another, the passes of said rolls being of elliptical form, the major axis of each ellipse being parallel to the axis of the rolls of that set, and the minor axis of each pass being exactly equal in length to the major axis of the ellipse of the succeeding pass, together with a mandrel composed of sections equal in length to the distance between the center of one set of rolls and the center of the next, the cross-section of each of said sections of mandrel being a slightly-reduced copy of the pass of the set of rolls Within the bite of which that section of the mandrel comes, substantially as described.

7. A mandrel consisting of a central stem and a series of elliptically-shaped sections keyed on said stem, the major axis of each section being equal in length to the minor axis of the preceding section and parallel thereto, substantially as described.

8. The combination of two or more sets of rolls set at right angles to each other,having elliptical passes with their major axes parallel to the axes of such rolls, and the diil'erence between the major axis and the minor axis of the same ellipse being reduced in each successive pass or set of rolls, ending with the last pass a true circle, together with a mandrel of elliptical sections secured on a stem, the difference between the major axis and the minor axis of each successive section being similarly diminished so that the last section of the mandrel is a true circle, substantially as shown and described.

In testimony whereof I allix mysignature in presence of two witnesses.

WILLIAM IIEOKERT.

Witnesses:

RALPH K. JoNEs, \V. F. ALMY. 

